Search engines are generally designed with the intent to simplify users' lives by helping them find relevant search results (e.g., documents) that match their search queries in a fast and effective way. For instance, users of search engines may compose and submit search queries in order conduct an online search for a service, product, particular information, or any other data targeted by the user intent behind the search query. Often, the set of search results generated by the conventional search engines are of poor quality, meaning that at least a portion of the set of search results does not properly satisfy the user's intent behind the search query. Specifically, in one study, researchers discovered that the top-listed results in roughly one in ten sets of search results were irrelevant to the user's intent of the corresponding search query.
There are various reasons for generating poor-quality search results. Some reasons involve a lack of good-quality documents in a web index being interrogated by the search engine or a failure of a core-ranking algorithm to locate the good-quality documents that exist within the web index.